Recently, in the field of photography, it is strongly desired to develop high-sensitivity photographic materials having excellent sharpness and color reproducibility.
As one means for improving the sharpness of photographic materials, it is known to use compounds which release a development inhibitor (DIR compounds) after the reaction of the compounds with the oxidation product of a developing agent. It is well known that the incorporation of such compounds into photographic emulsions results in the increase in the sharpness of color images to be formed due to their edge effect and also in the improvement in their color reproducibility due to their interlayer effect. For such DIR compounds, the development inhibiting effect and the diffusibility of the development inhibitor to be released therefrom during development are important factors. Compounds that have high interactivity with silver halides and have suitable hydrophobicity and diffusibility are suitable as development inhibitors. As DIR compounds capable of releasing such development inhibitors, for example, DIR compounds having a 1,2,3-triazole development inhibitor are known. Precisely, DIR couplers having a monocyclic triazole development inhibitor such as those described in EP 272573 and 401612 (corresponding to U.S. Pat. Nos. 5,200,306 and 5,021,331, respectively) and DIR couplers having a benzotriazole development inhibitor such as those described in U.S. Pat. Nos. 3,617,291, 3,933,500, 4,477,563 and 5,006,452 are known. However, the former DIR couplers having a monocyclic 1,2,3-triazole development inhibitor were disadvantageous with respect to the sharpness and the color reproducibility, since the development inhibiting effect of the development inhibitors to be released from them is low. The latter DIR compounds having a benzotriazole development inhibitor have an excellent interlayer effect, but further improvement of them in their sharpness was still desired.
Recently, rapid processing of photographic materials has become desired increasingly, therefore couplers having an excellent coloring property are desired.
As mentioned above, further improvement of the conventional DIR compounds having a monocyclic triazole development inhibitor in their sharpness, graininess and interlayer effect was desired. On the other hand, the conventional DIR compounds having a benzotriazole development inhibitor have an excellent interlayer effect, but further improvement of them in their sharpness and graininess was still desired. As DIR compounds themselves, those that may react rapidly with oxidation products of developing agents and those that are stable as DIR compounds have been desired.